Body supporting structures, including for example office chairs, vehicular and aircraft seating, sofas, beds and other pieces of furniture, may be configured with a backrest or seat that is flexible, and may change shape in response to a load applied by a user. In some embodiments, the amount of flexibility of the seat and/or back is predetermined, and may not be adjusted by the user. As such, the user may lack the ability to tune the stiffness/flexibility of the body supporting structure.
In other embodiments, the shape of the body support structure may be altered, for example by adjusting a lumbar support. Typically, such adjustments are not dynamic, but rather depend on a user input, for example to apply more or less tension to a lumbar support. In this way, the adjustments are made reactively, rather than proactively. In addition, the mechanisms for making such adjustments are often bulky, and may interfere with the aesthetics of the seating structure, for example when disposed across an open backrest. Moreover, the mechanisms may include various moving parts that are subject to failure and require replacement and maintenance over time.
In some embodiments, for example automotive or aircraft seating, powered adjustment mechanisms may require relatively large amounts of energy. Conversely, seating structures that are not tethered to a power source, such as office chairs, require a manual input for the adjustment mechanism, which often requires a bulky user interface.